thanks Chris, well spotted ......... It doesn't appear that any of us had commented earlier in this thread re Colin Lattimore's caption to his picture of the two trucks, both shown in the same photograph in his book, and for which he doesn't provide information to support his contention that the smaller truck is also a Hepple design........... although it may possibly be theirs of course.
We are accustomed to knowing that British C19 factories Registered, frequently, a basic shape in pressed glass, to which later decorative additions were added. However, it's confusing with instances such as these trucks, to feel confident one way or the other as to maker, when there is substantial size difference plus design alterations.
To quote from Colin Lattimore's book - regarding Hepple's 1880 novel designs ............ "" a sugar basin in the form of a coal scuttle; a container in various sizes in the form of a coal truck used in the collieries (see plate 68), which presumably could be used for either sugar or salt according to its size; and finally a wheelbarrow with the design imitating wooden planking.""
Even with Hepple's 1880 Registration of their 'coal truck' design, this would have only prevented other U.K. factories from doing the same for the three year protection afforded by the registration - after which copying someone else's design was fair game.
Do we know the source of Lattimore's statement .......... "various sizes in the form of a coal truck" - he may well have obtained this information from the Pottery Gazette or a Hepple catalogue for all I know - but certainly from information in this thread it doesn't appear that there are any known smaller six spoked trucks carrying Hepple Registration details.
It does seem that this larger truck is the only known size carrying Registration details for Hepple, which may or may not support Roy's comments that "I do not think they would have made 2 different coal trucks."

Presumably the Greener truck to which Fred refers carries that factory's Registration details - don't think I've ever seen one, and don't know when it was Registered.
That's my two pennyworth.

P.S. just to repeat that the Hepple truck Registration 351191 is from June 1880 and not 1890
